| 摘要 |
<p>In normal circumstances, the inlet e.m. valve (16) is de-energised and the analyser input valve (10) is energised, allowing the gas to be sampled to be drawn through the analyser (28), via a flow-rate controller (14), by a pump (30). If the gas to be sampled is: at too high a temp.; at too great a concn. for the analyser or is too humid, a supply of uncontaminated gas or air (27) can be added to the supply which is to be analysed. The fresh supply is fed via another flow controller (26), an inlet valve (24) and a circulation control valve (21). The fresh supply can also be used for flushing out the system at intervals.</p> |
